Various types of folding knives having push buttons for unlocking a blade from a locked position are known. Such knives typically are complicated and require a relatively large number of parts. One example is disclosed in U.S. Pat. No. 4,148,140, which discloses a ball latch mechanism that can lock the blade in one of several positions. What is needed is a much simpler locking mechanism for a folding knife having a push button or similar mechanism for disengaging the locking mechanism.